Julie Gerberding is a physician and an expert in infectious diseases. As director of the Centers for Disease Control and Prevention (CDC), she also holds what may be the most important medical job in the United States since the CDC is the federal agency in charge of protecting the health and safety of the American public.

Brian Graden has the knack—the knack for knowing what twenty-year-olds want to watch when they grab the remote control. As president of entertainment for MTV and VH1, Graden is responsible for deciding which programs will be the next big hits and which ones are destined to fizzle.

With his hip New York wardrobe, salt-and-pepper hair, and quick grin, Brian Greene looks more like a forty-something Justin Timber-lake than the scientist that he is. In fact, Greene is considered one of the top physicists in the United States and a leading expert in the field of superstring theory, which asserts that all matter is made up of tiny vibrating loops of energy.

Deborah Gregory had already achieved success in several careers, including working as a fashion model, entertainer, and magazine columnist, when she was approached in 1999 by Disney to create a series of books aimed at young African American girls. Because of her flamboyant personality and her flair for words, Gregory was just the right person to reach a marketing segment that had been traditionally overlooked.

For roboticist Helen Greiner the future is not found in the pages of a science fiction novel; the future is here and now. As president and cofounder of the iRobot Corporation, she is responsible for helping to advance the accessibility of robots, which are mechanical devices that perform functions automatically or by remote control.

Josh Groban is not a typical twenty-something pop singer, and record store owners have had a tough time deciding just what bin to put his CDs in. Many of his songs are contemporary romantic ballads, but Groban, who is classically trained, also performs opera and sings classical songs in Italian, Spanish, and French.

According to Newsweek magazine, Tony Hawk is the "most famous skateboarder, like, ever." A big claim, but with a lot to support it. In the 1980s and 1990s, Hawk almost single-handedly transformed skateboarding from a kids' parking-lot pastime into a respected sport.

Beginning in the 1970s, Saddam Hussein ruled the Republic of Iraq with a tight grip. His supporters maintained that through his many social and economic programs he effectively brought the country into the modern age.

By the mid-2000s, the press was calling Australian actor Hugh Jackman a jack-of-all-trades. American moviegoers lined up to see him in the X-Men blockbusters, in which he played the ultimate alternative superhero: the brooding, razor-clawed mutant known as Wolverine.

Peter Jackson made a name for himself in the movie industry with a small collection of gory, low-budget horror films including Dead Alive and The Frighteners. He worked from his native New Zealand, more than six thousand miles from Hollywood.

Before LeBron James had completed his sophomore year of high school, basketball scouts were discussing his chances of playing for the National Basketball Association (NBA). Before playing his first regulation game for the NBA, James had signed deals with Nike and other corporations for multimillion-dollar product endorsements.

In the mid-2000s a bevy of young, female singers, including Ashlee Simpson (1984–) and Hilary Duff (1987–), comfortably dominated the music charts. The youngest member of the growing pack was a supreme talent out of Massachusetts named Joanna Levesque, better known to fans as JoJo.

Computers had been around long before Steve Jobs entered the field, but his contributions revolutionized the personal-computer industry. As the cofounder of Apple in 1976, Jobs introduced the concept of a small, relatively inexpensive desktop computer that the average person could own and operate.

With her tousled blonde hair, full lips, and porcelain complexion, twenty-year-old Scarlett Johansson has become one of the hottest talents in Hollywood. In the mid-2000s her luminous features graced the cover of every fashion magazine, and in late 2004 she became the face of Calvin Klein, tapped to plug a new perfume for the famous designer.

Since 1989 Angela Johnson has been steadily producing exceptional books for young people, ranging from picture books for children to novels, poetry, and short stories for young adults. Her works have earned her the adoration of fans and the admiration of reviewers, many of whom have commented on her exceptional ability to create memorable, real characters who stay in readers' minds long after the book cover has been closed.

In 2002 Norah Jones, age twenty-two, released her debut full-length album, Come Away with Me. A low-key, acoustic work that defies categorization but includes hints of jazz, traditional pop, country, and folk; the CD is the kind of recording that would ordinarily have sold several thousand copies, earned admiring reviews in the music press, and then faded from view.

Since publishing her first novel, The Floating World, in 1989, Cynthia Kadohata has been viewed as one of the most compelling novelists in the United States. At the same time, she has tended to be described as a Japanese American writer, a distinction the author feels is both flattering and misleading.

Dean Kamen is a leading American scientist and inventor whose products include the Segway human transporter (HT) and the iBOT battery-powered wheelchair. His numerous inventions include medical devices and futuristic gizmos that Kamen hopes will revolutionize the way we live and travel.

For most of his life Hamid Karzai has dedicated himself to bringing peace and unity to his homeland of Afghanistan, a nearly impossible task because the country has been plagued by internal tensions and external threats for decades. During the 1980s, when Afghanistan was controlled by Soviet forces, Karzai fled to Pakistan, where he served as director for the Afghan National Liberation Front.

From her early childhood, Beyoncé Knowles wanted to be more than a performer: she wanted to be a superstar. By the age of twenty-one, she had reached that goal, becoming world-famous not just in her chosen field of singing but also as an actress.

For three years, from 2000 until 2003, most people knew him as the mop-headed, wise-cracking younger brother Louis on the top-rated Disney Channel series Even Stevens. But in 2003, thanks to his breakthrough lead role in the movie Holes, teen actor Shia LaBeouf made an almost seamless transition from the small screen to the big screen.